The alkylation of aromatics with a variety of Lewis or Bronsted acid catalysts is well known. Typical commercial catalysts include phosphoric acid/kieselguhr, aluminum chloride, and hydrogen fluoride. Alkylation with lower molecular weight olefins, such as propylene, can be carried out in the liquid or vapor phase. For alkylations with higher olefins, such as C.sub.16+ olefins, the alkylations are done in the liquid phase, usually in the presence of hydrogen fluoride. Alkylations of benzene with higher olefins is especially difficult, and requires hydrogen fluoride treatment. Such a process is disclosed by Himes in U.S. Pat. No. 4,503,277, entitled "HF Regeneration in Aromatic Hydrocarbon Alkylation Process," which is hereby incorporated by reference in its entirety for all purposes.
It has been found that in some cases, in the alkylation of aromatics with long chain olefins, conversion is insufficient to remove the last traces of olefins. When excess aromatic is stripped from the product, the residual high boiling long chain olefins are not distilled out. This residual olefin can lead to poor product properties.
U.S. Pat. No. 4,795,550 discloses a process for reducing the residual olefin content from hydrocarbon process streams containing substantially aromatic and napthenic hydrocarbons having from 6 to 20 carbon atoms per molecule. This process occurs at reaction conditions which ensure liquid phase operation with a solid catalyst, preferably zeolite Y, in a fixed bed reactor operating at a liquid hourly space velocity of 1 to 10 hour.sup.-1 by a catalytic olefin-consuming alkylation reaction to produce an essentially olefin-free product. The essentially olefin-free product has approximately the same quantity and distribution of aromatic and napthenic hydrocarbons as contained in the original process stream. U.S. Pat. No. 4,795,550 is hereby incorporated by reference in its entirety for all purposes.